An internal combustion engine utilizes fuel and air under pressure to create an explosion, or controlled burn, in a combustion chamber to convert translational energy into rotational energy. This rotational energy may be applied to the drive wheels of a vehicle, the propeller of a boat, airplane or any rotary device.
In a carbureted system, the operator may adjust the size of the orfice or jets which are used to transfer the fuel from the fuel holding area of the carburetor to the air column to adjust for possible changes in atmospheric conditions. This may present a disadvantage for some carbureted engines in that the jets must be changed manually and are therefore not typically electronically controlled.
In addition, the intake manifold of an engine is designed to deliver equal quantities of the air-fuel charge to each cylinder, such as but not limited to passenger vehicles which typically have 4 to 12 cylinders, while preventing the charge from one cylinder to interfere with the flow of the charge to another.
Many factors may influence the flow of charge to the individual cylinders including the number of cylinders, their geometric orientation which may be a “V” style or aligned linearly with the cylinders in a row. Other factors may include the depth and diameter of the cylinders, the throttle position—whether it is wide-open or closed as in the idle position, the cross-sectional area of each runner which directs the charge to an individual cylinder and numerous other factors not specifically listed here. Some rise tracts leading to each cylinder are designed to produce a minimum idling air velocity which can support the heavier fuel particles in the air stream while remaining large enough to support combustion at wide open throttle. In some cases, the optimum manifold design for a low engine speeds may not be optimum for a high speed engine due the pressure-waves created in the manifold tracks and the opening and closing of the intake valve. As the intake valve opens, the pressure in the cylinder may be reduced thereby creating a negative pressure-wave, which travels through the air column to the atmosphere, influencing the delivery of the charge to the remaining cylinders. Similarly, as the engine speed increases, the duration of time the intake valve is open decreases, thereby decreasing the volumetric efficiency of the engine. It would therefore be beneficial to design a manifold which provides for a large amount of volumetric efficiency based on the particular engine configuration over the range of operating conditions from closed to wide open throttle.
Centrifugal superchargers may increase the pressure of the intake air by utilizing a compressor powered by the engine. It would therefore be beneficial to provide a positive displacement pump such as but not limited to the vane, rotor style superchargers which may provide a charge output which is directly proportional to the speed at which the rotor blade is rotating.
In addition, some root, screw or vane style superchargers require a larger foot print within the engine compartment and may cause an increase in weight to a particular vehicle. Some vane, root and screw-style superchargers are positioned above the intake manifold to force the compressed charge into the cylinders. However, these root, screw or vane style superchargers may have limited use because they are designed to be placed at a particular location within a particular model of a vehicle. It would therefore be beneficial to provide a rotary style centrifugal supercharger having a compact design which can be utilized in a supercharger application, in addition, it would be beneficial to allow for the positioning of the supercharger at a number of different locations within the engine compartment, or within a number of different models of vehicles.
While a supercharger, may be driven with a crankshaft connected to a belt which is associated with the supercharger, a balancer may be mounted on the crankshaft, obstructing the crankshaft of the engine. In some instances, the clearance of the balancer mounted on the crankshaft in combination with surrounding components may limit the ability to connect the supercharger to the crankshaft. In addition, attaching and driving the supercharger belt may require utilizing an aftermarket harmonic balancer having tapered and threaded holes for mating to the drive pulley. However, it is often difficult to replace the balancer with an aftermarket balancer due to the limited space in the engine compartment. In some cases, components may need to be removed or worse, the engine may need to be raised or removed to gain access to the crankshaft. In addition, in some cases replacing the original equipment manufacturer (OEM) with an aftermarket harmonic balancer increases the over cost of installing a supercharger system. It would therefore be beneficial to provide a harmonic balancer which does not require the removal or raising of the engine, does not cause an increased expense to the installation of a supercharger system and does not require the purchase of an aftermarket balancer pulley.
Another concern in supercharger installation applications is the alignment of the supercharger belt. Improper belt alignment may cause the supercharger to fail or may cause excessive wear to the supercharger belt which may lead to failure of the supercharger system. In addition, alignment of the supercharger belt may be difficult in a compact engine compartment. Thus, when it is impractical to replace the balancer with an aftermarket harmonic balancer or if belt alignment is a concern, an installer may elect to drive the supercharger belt at another location such as the alternator, water pump or power-steering pulley. This may result in a loss of engine horsepower. Furthermore, there are safety issues with using accessory drive pulleys such as power-steering pump or alternator pulleys. If the belt or supercharger fails, the operator will loose the use of accessory drive pulleys. Therefore, it would be beneficial to provide a method and apparatus for mechanically driving an engine with a drive pulley associated with the harmonic balancer which can be mounted in compact engine compartments, minimizes the loss of horsepower and does not cause safety concerns associated with mounting the belt on an accessory drive pulley.
Additionally, engaging the drive pulley at an alternative location may limit the width of the pulley belt which can be used. A wider drive belt may allow for increased horsepower applied to the pulley and supercharger. However, attaching the supercharger at an alternative drive pulley location may limit the belt to a six ribbed belt, potentially limiting the amount of horsepower. It would therefore be beneficial to provide for the use of a wider ribbed belt for driving the pulley by the engine crankshaft via the harmonic balancer. It is therefore, advantageous to develop a belt drive pulley that can be driven by the crankshaft at the harmonic balancer, reducing the cost of a supercharger system and that can be installed without pulling the motor out of the engine compartment.